function qrcode(options) {
    // if options is string, 
    if (typeof options === 'string') {
        options = {
            text: options
        };
    }
 
    options = Object.assign({}, {
        render: "canvas",
        width: 256,
        height: 256,
        typeNumber: -1,
        correctLevel: QRErrorCorrectLevel.H,
        background: "#ffffff",
        foreground: "#000000"
    }, options);
    var createCanvas = function createCanvas() {
        const dpr = wx.getSystemInfoSync().pixelRatio / 3.5
        const width = options.width
        // create the qrcode itself
        var qrcode = new QRCode(options.typeNumber, options.correctLevel);
        qrcode.addData(options.text);
        qrcode.make(); // 使用 wx.createContext 获取绘图上下文 context
 
        var ctx = wx.createCanvasContext(options.canvasId); // compute tileW/tileH based on options.width/options.height
 
        var tileW = options.width / qrcode.getModuleCount();
        var tileH = options.height / qrcode.getModuleCount(); // draw in the canvas
 
        for (var row = 0; row < qrcode.getModuleCount(); row++) {
            for (var col = 0; col < qrcode.getModuleCount(); col++) {
                var fillStyle = qrcode.isDark(row, col) ? options.foreground : options.background;
                ctx.setFillStyle(fillStyle);
                var w = Math.ceil((col + 1) * tileW) - Math.floor(col * tileW);
                var h = Math.ceil((row + 1) * tileH) - Math.floor(row * tileH);
                ctx.fillRect(Math.round(col * tileW), Math.round(row * tileH), w, h);
            }
        }
 
        if (options.image.imageResource) {
            const imgW = options.image.width * dpr
            const imgH = options.image.height * dpr
            const dx = (width - imgW) / 2
            const dy = (width - imgH) / 2
            if (options.image.round) {
                // Logo边框
                const imgW2 = options.image.width * dpr + 30
                const dx2 = (width - imgW2) / 2
                const r2 = imgW2 / 2
                const cx2 = dx2 + r2;
                ctx.beginPath();
                ctx.arc(cx2, cx2, r2, 0, 2 * Math.PI);
                ctx.fillStyle = '#ffffff'
                ctx.fill();
                ctx.restore();
 
                // 画Logo
                const r = imgW / 2
                const cx = dx + r;
                const cy = dy + r;
                ctx.beginPath();
                ctx.arc(cx, cy, r, 0, 2 * Math.PI);
                ctx.clip();
 
                ctx.drawImage(options.image.imageResource, dx, dy, imgW, imgW);
                ctx.restore();
            } else {
                ctx.drawImage(options.image.imageResource, dx, dy, imgW, imgH)
                ctx.restore();
            }
        }
 
 
        ctx.draw(true);
    };
 
    createCanvas();
} 
//---------------------------------------------------------------------
// QRCode for JavaScript
//
// Copyright (c) 2009 Kazuhiko Arase
//
// URL: http://www.d-project.com/
//
// Licensed under the MIT license:
//   http://www.opensource.org/licenses/mit-license.php
//
// The word "QR Code" is registered trademark of 
// DENSO WAVE INCORPORATED
//   http://www.denso-wave.com/qrcode/faqpatent-e.html
//
//---------------------------------------------------------------------
//---------------------------------------------------------------------
// QR8bitByte
//---------------------------------------------------------------------
 
 
function QR8bitByte(data) {
    this.mode = QRMode.MODE_8BIT_BYTE;
    this.data = data;
}
 
QR8bitByte.prototype = {
    getLength: function getLength(buffer) {
        return this.data.length;
    },
    write: function write(buffer) {
        for (var i = 0; i < this.data.length; i++) {
            // not JIS ...
            buffer.put(this.data.charCodeAt(i), 8);
        }
    }
}; 
//---------------------------------------------------------------------
// QRCode
//---------------------------------------------------------------------
 
function QRCode(typeNumber, errorCorrectLevel) {
    this.typeNumber = typeNumber;
    this.errorCorrectLevel = errorCorrectLevel;
    this.modules = null;
    this.moduleCount = 0;
    this.dataCache = null;
    this.dataList = new Array();
}
 
QRCode.prototype = {
    addData: function addData(data) {
        var newData = new QR8bitByte(data);
        this.dataList.push(newData);
        this.dataCache = null;
    },
    isDark: function isDark(row, col) {
        if (row < 0 || this.moduleCount <= row || col < 0 || this.moduleCount <= col) {
            throw new Error(row + "," + col);
        }
 
        return this.modules[row][col];
    },
    getModuleCount: function getModuleCount() {
        return this.moduleCount;
    },
    make: function make() {
        // Calculate automatically typeNumber if provided is < 1
        if (this.typeNumber < 1) {
            var typeNumber = 1;
 
            for (typeNumber = 1; typeNumber < 40; typeNumber++) {
                var rsBlocks = QRRSBlock.getRSBlocks(typeNumber, this.errorCorrectLevel);
                var buffer = new QRBitBuffer();
                var totalDataCount = 0;
 
                for (var i = 0; i < rsBlocks.length; i++) {
                    totalDataCount += rsBlocks[i].dataCount;
                }
 
                for (var i = 0; i < this.dataList.length; i++) {
                    var data = this.dataList[i];
                    buffer.put(data.mode, 4);
                    buffer.put(data.getLength(), QRUtil.getLengthInBits(data.mode, typeNumber));
                    data.write(buffer);
                }
 
                if (buffer.getLengthInBits() <= totalDataCount * 8) break;
            }
 
            this.typeNumber = typeNumber;
        }
 
        this.makeImpl(false, this.getBestMaskPattern());
    },
    makeImpl: function makeImpl(test, maskPattern) {
        this.moduleCount = this.typeNumber * 4 + 17;
        this.modules = new Array(this.moduleCount);
 
        for (var row = 0; row < this.moduleCount; row++) {
            this.modules[row] = new Array(this.moduleCount);
 
            for (var col = 0; col < this.moduleCount; col++) {
                this.modules[row][col] = null; //(col + row) % 3;
            }
        }
 
        this.setupPositionProbePattern(0, 0);
        this.setupPositionProbePattern(this.moduleCount - 7, 0);
        this.setupPositionProbePattern(0, this.moduleCount - 7);
        this.setupPositionAdjustPattern();
        this.setupTimingPattern();
        this.setupTypeInfo(test, maskPattern);
 
        if (this.typeNumber >= 7) {
            this.setupTypeNumber(test);
        }
 
        if (this.dataCache == null) {
            this.dataCache = QRCode.createData(this.typeNumber, this.errorCorrectLevel, this.dataList);
        }
 
        this.mapData(this.dataCache, maskPattern);
    },
    setupPositionProbePattern: function setupPositionProbePattern(row, col) {
        for (var r = -1; r <= 7; r++) {
            if (row + r <= -1 || this.moduleCount <= row + r) continue;
 
            for (var c = -1; c <= 7; c++) {
                if (col + c <= -1 || this.moduleCount <= col + c) continue;
 
                if (0 <= r && r <= 6 && (c == 0 || c == 6) || 0 <= c && c <= 6 && (r == 0 || r == 6) || 2 <= r && r <= 4 && 2 <= c && c <= 4) {
                    this.modules[row + r][col + c] = true;
                } else {
                    this.modules[row + r][col + c] = false;
                }
            }
        }
    },
    getBestMaskPattern: function getBestMaskPattern() {
        var minLostPoint = 0;
        var pattern = 0;
 
        for (var i = 0; i < 8; i++) {
            this.makeImpl(true, i);
            var lostPoint = QRUtil.getLostPoint(this);
 
            if (i == 0 || minLostPoint > lostPoint) {
                minLostPoint = lostPoint;
                pattern = i;
            }
        }
 
        return pattern;
    },
    createMovieClip: function createMovieClip(target_mc, instance_name, depth) {
        var qr_mc = target_mc.createEmptyMovieClip(instance_name, depth);
        var cs = 1;
        this.make();
 
        for (var row = 0; row < this.modules.length; row++) {
            var y = row * cs;
 
            for (var col = 0; col < this.modules[row].length; col++) {
                var x = col * cs;
                var dark = this.modules[row][col];
 
                if (dark) {
                    qr_mc.beginFill(0, 100);
                    qr_mc.moveTo(x, y);
                    qr_mc.lineTo(x + cs, y);
                    qr_mc.lineTo(x + cs, y + cs);
                    qr_mc.lineTo(x, y + cs);
                    qr_mc.endFill();
                }
            }
        }
 
        return qr_mc;
    },
    setupTimingPattern: function setupTimingPattern() {
        for (var r = 8; r < this.moduleCount - 8; r++) {
            if (this.modules[r][6] != null) {
                continue;
            }
 
            this.modules[r][6] = r % 2 == 0;
        }
 
        for (var c = 8; c < this.moduleCount - 8; c++) {
            if (this.modules[6][c] != null) {
                continue;
            }
 
            this.modules[6][c] = c % 2 == 0;
        }
    },
    setupPositionAdjustPattern: function setupPositionAdjustPattern() {
        var pos = QRUtil.getPatternPosition(this.typeNumber);
 
        for (var i = 0; i < pos.length; i++) {
            for (var j = 0; j < pos.length; j++) {
                var row = pos[i];
                var col = pos[j];
 
                if (this.modules[row][col] != null) {
                    continue;
                }
 
                for (var r = -2; r <= 2; r++) {
                    for (var c = -2; c <= 2; c++) {
                        if (r == -2 || r == 2 || c == -2 || c == 2 || r == 0 && c == 0) {
                            this.modules[row + r][col + c] = true;
                        } else {
                            this.modules[row + r][col + c] = false;
                        }
                    }
                }
            }
        }
    },
    setupTypeNumber: function setupTypeNumber(test) {
        var bits = QRUtil.getBCHTypeNumber(this.typeNumber);
 
        for (var i = 0; i < 18; i++) {
            var mod = !test && (bits >> i & 1) == 1;
            this.modules[Math.floor(i / 3)][i % 3 + this.moduleCount - 8 - 3] = mod;
        }
 
        for (var i = 0; i < 18; i++) {
            var mod = !test && (bits >> i & 1) == 1;
            this.modules[i % 3 + this.moduleCount - 8 - 3][Math.floor(i / 3)] = mod;
        }
    },
    setupTypeInfo: function setupTypeInfo(test, maskPattern) {
        var data = this.errorCorrectLevel << 3 | maskPattern;
        var bits = QRUtil.getBCHTypeInfo(data); // vertical   
 
        for (var i = 0; i < 15; i++) {
            var mod = !test && (bits >> i & 1) == 1;
 
            if (i < 6) {
                this.modules[i][8] = mod;
            } else if (i < 8) {
                this.modules[i + 1][8] = mod;
            } else {
                this.modules[this.moduleCount - 15 + i][8] = mod;
            }
        } // horizontal
 
 
        for (var i = 0; i < 15; i++) {
            var mod = !test && (bits >> i & 1) == 1;
 
            if (i < 8) {
                this.modules[8][this.moduleCount - i - 1] = mod;
            } else if (i < 9) {
                this.modules[8][15 - i - 1 + 1] = mod;
            } else {
                this.modules[8][15 - i - 1] = mod;
            }
        } // fixed module
 
 
        this.modules[this.moduleCount - 8][8] = !test;
    },
    mapData: function mapData(data, maskPattern) {
        var inc = -1;
        var row = this.moduleCount - 1;
        var bitIndex = 7;
        var byteIndex = 0;
 
        for (var col = this.moduleCount - 1; col > 0; col -= 2) {
            if (col == 6) col--;
 
            while (true) {
                for (var c = 0; c < 2; c++) {
                    if (this.modules[row][col - c] == null) {
                        var dark = false;
 
                        if (byteIndex < data.length) {
                            dark = (data[byteIndex] >>> bitIndex & 1) == 1;
                        }
 
                        var mask = QRUtil.getMask(maskPattern, row, col - c);
 
                        if (mask) {
                            dark = !dark;
                        }
 
                        this.modules[row][col - c] = dark;
                        bitIndex--;
 
                        if (bitIndex == -1) {
                            byteIndex++;
                            bitIndex = 7;
                        }
                    }
                }
 
                row += inc;
 
                if (row < 0 || this.moduleCount <= row) {
                    row -= inc;
                    inc = -inc;
                    break;
                }
            }
        }
    }
};
QRCode.PAD0 = 0xEC;
QRCode.PAD1 = 0x11;
 
QRCode.createData = function (typeNumber, errorCorrectLevel, dataList) {
    var rsBlocks = QRRSBlock.getRSBlocks(typeNumber, errorCorrectLevel);
    var buffer = new QRBitBuffer();
 
    for (var i = 0; i < dataList.length; i++) {
        var data = dataList[i];
        buffer.put(data.mode, 4);
        buffer.put(data.getLength(), QRUtil.getLengthInBits(data.mode, typeNumber));
        data.write(buffer);
    } // calc num max data.
 
 
    var totalDataCount = 0;
 
    for (var i = 0; i < rsBlocks.length; i++) {
        totalDataCount += rsBlocks[i].dataCount;
    }
 
    if (buffer.getLengthInBits() > totalDataCount * 8) {
        throw new Error("code length overflow. (" + buffer.getLengthInBits() + ">" + totalDataCount * 8 + ")");
    } // end code
 
 
    if (buffer.getLengthInBits() + 4 <= totalDataCount * 8) {
        buffer.put(0, 4);
    } // padding
 
 
    while (buffer.getLengthInBits() % 8 != 0) {
        buffer.putBit(false);
    } // padding
 
 
    while (true) {
        if (buffer.getLengthInBits() >= totalDataCount * 8) {
            break;
        }
 
        buffer.put(QRCode.PAD0, 8);
 
        if (buffer.getLengthInBits() >= totalDataCount * 8) {
            break;
        }
 
        buffer.put(QRCode.PAD1, 8);
    }
 
    return QRCode.createBytes(buffer, rsBlocks);
};
 
QRCode.createBytes = function (buffer, rsBlocks) {
    var offset = 0;
    var maxDcCount = 0;
    var maxEcCount = 0;
    var dcdata = new Array(rsBlocks.length);
    var ecdata = new Array(rsBlocks.length);
 
    for (var r = 0; r < rsBlocks.length; r++) {
        var dcCount = rsBlocks[r].dataCount;
        var ecCount = rsBlocks[r].totalCount - dcCount;
        maxDcCount = Math.max(maxDcCount, dcCount);
        maxEcCount = Math.max(maxEcCount, ecCount);
        dcdata[r] = new Array(dcCount);
 
        for (var i = 0; i < dcdata[r].length; i++) {
            dcdata[r][i] = 0xff & buffer.buffer[i + offset];
        }
 
        offset += dcCount;
        var rsPoly = QRUtil.getErrorCorrectPolynomial(ecCount);
        var rawPoly = new QRPolynomial(dcdata[r], rsPoly.getLength() - 1);
        var modPoly = rawPoly.mod(rsPoly);
        ecdata[r] = new Array(rsPoly.getLength() - 1);
 
        for (var i = 0; i < ecdata[r].length; i++) {
            var modIndex = i + modPoly.getLength() - ecdata[r].length;
            ecdata[r][i] = modIndex >= 0 ? modPoly.get(modIndex) : 0;
        }
    }
 
    var totalCodeCount = 0;
 
    for (var i = 0; i < rsBlocks.length; i++) {
        totalCodeCount += rsBlocks[i].totalCount;
    }
 
    var data = new Array(totalCodeCount);
    var index = 0;
 
    for (var i = 0; i < maxDcCount; i++) {
        for (var r = 0; r < rsBlocks.length; r++) {
            if (i < dcdata[r].length) {
                data[index++] = dcdata[r][i];
            }
        }
    }
 
    for (var i = 0; i < maxEcCount; i++) {
        for (var r = 0; r < rsBlocks.length; r++) {
            if (i < ecdata[r].length) {
                data[index++] = ecdata[r][i];
            }
        }
    }
 
    return data;
}; 
 
//---------------------------------------------------------------------
// QRMode
//---------------------------------------------------------------------
 
 
var QRMode = {
    MODE_NUMBER: 1 << 0,
    MODE_ALPHA_NUM: 1 << 1,
    MODE_8BIT_BYTE: 1 << 2,
    MODE_KANJI: 1 << 3
}; 
 
//---------------------------------------------------------------------
// QRErrorCorrectLevel
//---------------------------------------------------------------------
 
var QRErrorCorrectLevel = {
    L: 1,
    M: 0,
    Q: 3,
    H: 2
}; 
 
//---------------------------------------------------------------------
// QRMaskPattern
//---------------------------------------------------------------------
 
var QRMaskPattern = {
    PATTERN000: 0,
    PATTERN001: 1,
    PATTERN010: 2,
    PATTERN011: 3,
    PATTERN100: 4,
    PATTERN101: 5,
    PATTERN110: 6,
    PATTERN111: 7
}; 
 
//---------------------------------------------------------------------
// QRUtil
//---------------------------------------------------------------------
 
var QRUtil = {
    PATTERN_POSITION_TABLE: [[], [6, 18], [6, 22], [6, 26], [6, 30], [6, 34], [6, 22, 38], [6, 24, 42], [6, 26, 46], [6, 28, 50], [6, 30, 54], [6, 32, 58], [6, 34, 62], [6, 26, 46, 66], [6, 26, 48, 70], [6, 26, 50, 74], [6, 30, 54, 78], [6, 30, 56, 82], [6, 30, 58, 86], [6, 34, 62, 90], [6, 28, 50, 72, 94], [6, 26, 50, 74, 98], [6, 30, 54, 78, 102], [6, 28, 54, 80, 106], [6, 32, 58, 84, 110], [6, 30, 58, 86, 114], [6, 34, 62, 90, 118], [6, 26, 50, 74, 98, 122], [6, 30, 54, 78, 102, 126], [6, 26, 52, 78, 104, 130], [6, 30, 56, 82, 108, 134], [6, 34, 60, 86, 112, 138], [6, 30, 58, 86, 114, 142], [6, 34, 62, 90, 118, 146], [6, 30, 54, 78, 102, 126, 150], [6, 24, 50, 76, 102, 128, 154], [6, 28, 54, 80, 106, 132, 158], [6, 32, 58, 84, 110, 136, 162], [6, 26, 54, 82, 110, 138, 166], [6, 30, 58, 86, 114, 142, 170]],
    G15: 1 << 10 | 1 << 8 | 1 << 5 | 1 << 4 | 1 << 2 | 1 << 1 | 1 << 0,
    G18: 1 << 12 | 1 << 11 | 1 << 10 | 1 << 9 | 1 << 8 | 1 << 5 | 1 << 2 | 1 << 0,
    G15_MASK: 1 << 14 | 1 << 12 | 1 << 10 | 1 << 4 | 1 << 1,
    getBCHTypeInfo: function getBCHTypeInfo(data) {
        var d = data << 10;
 
        while (QRUtil.getBCHDigit(d) - QRUtil.getBCHDigit(QRUtil.G15) >= 0) {
            d ^= QRUtil.G15 << QRUtil.getBCHDigit(d) - QRUtil.getBCHDigit(QRUtil.G15);
        }
 
        return (data << 10 | d) ^ QRUtil.G15_MASK;
    },
    getBCHTypeNumber: function getBCHTypeNumber(data) {
        var d = data << 12;
 
        while (QRUtil.getBCHDigit(d) - QRUtil.getBCHDigit(QRUtil.G18) >= 0) {
            d ^= QRUtil.G18 << QRUtil.getBCHDigit(d) - QRUtil.getBCHDigit(QRUtil.G18);
        }
 
        return data << 12 | d;
    },
    getBCHDigit: function getBCHDigit(data) {
        var digit = 0;
 
        while (data != 0) {
            digit++;
            data >>>= 1;
        }
 
        return digit;
    },
    getPatternPosition: function getPatternPosition(typeNumber) {
        return QRUtil.PATTERN_POSITION_TABLE[typeNumber - 1];
    },
    getMask: function getMask(maskPattern, i, j) {
        switch (maskPattern) {
            case QRMaskPattern.PATTERN000:
                return (i + j) % 2 == 0;
 
            case QRMaskPattern.PATTERN001:
                return i % 2 == 0;
 
            case QRMaskPattern.PATTERN010:
                return j % 3 == 0;
 
            case QRMaskPattern.PATTERN011:
                return (i + j) % 3 == 0;
 
            case QRMaskPattern.PATTERN100:
                return (Math.floor(i / 2) + Math.floor(j / 3)) % 2 == 0;
 
            case QRMaskPattern.PATTERN101:
                return i * j % 2 + i * j % 3 == 0;
 
            case QRMaskPattern.PATTERN110:
                return (i * j % 2 + i * j % 3) % 2 == 0;
 
            case QRMaskPattern.PATTERN111:
                return (i * j % 3 + (i + j) % 2) % 2 == 0;
 
            default:
                throw new Error("bad maskPattern:" + maskPattern);
        }
    },
    getErrorCorrectPolynomial: function getErrorCorrectPolynomial(errorCorrectLength) {
        var a = new QRPolynomial([1], 0);
 
        for (var i = 0; i < errorCorrectLength; i++) {
            a = a.multiply(new QRPolynomial([1, QRMath.gexp(i)], 0));
        }
 
        return a;
    },
    getLengthInBits: function getLengthInBits(mode, type) {
        if (1 <= type && type < 10) {
            // 1 - 9
            switch (mode) {
                case QRMode.MODE_NUMBER:
                    return 10;
 
                case QRMode.MODE_ALPHA_NUM:
                    return 9;
 
                case QRMode.MODE_8BIT_BYTE:
                    return 8;
 
                case QRMode.MODE_KANJI:
                    return 8;
 
                default:
                    throw new Error("mode:" + mode);
            }
        } else if (type < 27) {
            // 10 - 26
            switch (mode) {
                case QRMode.MODE_NUMBER:
                    return 12;
 
                case QRMode.MODE_ALPHA_NUM:
                    return 11;
 
                case QRMode.MODE_8BIT_BYTE:
                    return 16;
 
                case QRMode.MODE_KANJI:
                    return 10;
 
                default:
                    throw new Error("mode:" + mode);
            }
        } else if (type < 41) {
            // 27 - 40
            switch (mode) {
                case QRMode.MODE_NUMBER:
                    return 14;
 
                case QRMode.MODE_ALPHA_NUM:
                    return 13;
 
                case QRMode.MODE_8BIT_BYTE:
                    return 16;
 
                case QRMode.MODE_KANJI:
                    return 12;
 
                default:
                    throw new Error("mode:" + mode);
            }
        } else {
            throw new Error("type:" + type);
        }
    },
    getLostPoint: function getLostPoint(qrCode) {
        var moduleCount = qrCode.getModuleCount();
        var lostPoint = 0; // LEVEL1
 
        for (var row = 0; row < moduleCount; row++) {
            for (var col = 0; col < moduleCount; col++) {
                var sameCount = 0;
                var dark = qrCode.isDark(row, col);
 
                for (var r = -1; r <= 1; r++) {
                    if (row + r < 0 || moduleCount <= row + r) {
                        continue;
                    }
 
                    for (var c = -1; c <= 1; c++) {
                        if (col + c < 0 || moduleCount <= col + c) {
                            continue;
                        }
 
                        if (r == 0 && c == 0) {
                            continue;
                        }
 
                        if (dark == qrCode.isDark(row + r, col + c)) {
                            sameCount++;
                        }
                    }
                }
 
                if (sameCount > 5) {
                    lostPoint += 3 + sameCount - 5;
                }
            }
        } // LEVEL2
 
 
        for (var row = 0; row < moduleCount - 1; row++) {
            for (var col = 0; col < moduleCount - 1; col++) {
                var count = 0;
                if (qrCode.isDark(row, col)) count++;
                if (qrCode.isDark(row + 1, col)) count++;
                if (qrCode.isDark(row, col + 1)) count++;
                if (qrCode.isDark(row + 1, col + 1)) count++;
 
                if (count == 0 || count == 4) {
                    lostPoint += 3;
                }
            }
        } // LEVEL3
 
 
        for (var row = 0; row < moduleCount; row++) {
            for (var col = 0; col < moduleCount - 6; col++) {
                if (qrCode.isDark(row, col) && !qrCode.isDark(row, col + 1) && qrCode.isDark(row, col + 2) && qrCode.isDark(row, col + 3) && qrCode.isDark(row, col + 4) && !qrCode.isDark(row, col + 5) && qrCode.isDark(row, col + 6)) {
                    lostPoint += 40;
                }
            }
        }
 
        for (var col = 0; col < moduleCount; col++) {
            for (var row = 0; row < moduleCount - 6; row++) {
                if (qrCode.isDark(row, col) && !qrCode.isDark(row + 1, col) && qrCode.isDark(row + 2, col) && qrCode.isDark(row + 3, col) && qrCode.isDark(row + 4, col) && !qrCode.isDark(row + 5, col) && qrCode.isDark(row + 6, col)) {
                    lostPoint += 40;
                }
            }
        } // LEVEL4
 
 
        var darkCount = 0;
 
        for (var col = 0; col < moduleCount; col++) {
            for (var row = 0; row < moduleCount; row++) {
                if (qrCode.isDark(row, col)) {
                    darkCount++;
                }
            }
        }
 
        var ratio = Math.abs(100 * darkCount / moduleCount / moduleCount - 50) / 5;
        lostPoint += ratio * 10;
        return lostPoint;
    }
}; 
 
//---------------------------------------------------------------------
// QRMath
//---------------------------------------------------------------------
 
var QRMath = {
    glog: function glog(n) {
        if (n < 1) {
            throw new Error("glog(" + n + ")");
        }
 
        return QRMath.LOG_TABLE[n];
    },
    gexp: function gexp(n) {
        while (n < 0) {
            n += 255;
        }
 
        while (n >= 256) {
            n -= 255;
        }
 
        return QRMath.EXP_TABLE[n];
    },
    EXP_TABLE: new Array(256),
    LOG_TABLE: new Array(256)
};
 
for (var i = 0; i < 8; i++) {
    QRMath.EXP_TABLE[i] = 1 << i;
}
 
for (var i = 8; i < 256; i++) {
    QRMath.EXP_TABLE[i] = QRMath.EXP_TABLE[i - 4] ^ QRMath.EXP_TABLE[i - 5] ^ QRMath.EXP_TABLE[i - 6] ^ QRMath.EXP_TABLE[i - 8];
}
 
for (var i = 0; i < 255; i++) {
    QRMath.LOG_TABLE[QRMath.EXP_TABLE[i]] = i;
} 
 
//---------------------------------------------------------------------
// QRPolynomial
//---------------------------------------------------------------------
 
 
function QRPolynomial(num, shift) {
    if (num.length == undefined) {
        throw new Error(num.length + "/" + shift);
    }
 
    var offset = 0;
 
    while (offset < num.length && num[offset] == 0) {
        offset++;
    }
 
    this.num = new Array(num.length - offset + shift);
 
    for (var i = 0; i < num.length - offset; i++) {
        this.num[i] = num[i + offset];
    }
}
 
QRPolynomial.prototype = {
    get: function get(index) {
        return this.num[index];
    },
    getLength: function getLength() {
        return this.num.length;
    },
    multiply: function multiply(e) {
        var num = new Array(this.getLength() + e.getLength() - 1);
 
        for (var i = 0; i < this.getLength(); i++) {
            for (var j = 0; j < e.getLength(); j++) {
                num[i + j] ^= QRMath.gexp(QRMath.glog(this.get(i)) + QRMath.glog(e.get(j)));
            }
        }
 
        return new QRPolynomial(num, 0);
    },
    mod: function mod(e) {
        if (this.getLength() - e.getLength() < 0) {
            return this;
        }
 
        var ratio = QRMath.glog(this.get(0)) - QRMath.glog(e.get(0));
        var num = new Array(this.getLength());
 
        for (var i = 0; i < this.getLength(); i++) {
            num[i] = this.get(i);
        }
 
        for (var i = 0; i < e.getLength(); i++) {
            num[i] ^= QRMath.gexp(QRMath.glog(e.get(i)) + ratio);
        } // recursive call
 
 
        return new QRPolynomial(num, 0).mod(e);
    }
}; 
 
//---------------------------------------------------------------------
// QRRSBlock
//---------------------------------------------------------------------
 
function QRRSBlock(totalCount, dataCount) {
    this.totalCount = totalCount;
    this.dataCount = dataCount;
}
 
QRRSBlock.RS_BLOCK_TABLE = [// L
    // M
    // Q
    // H
    // 1
    [1, 26, 19], [1, 26, 16], [1, 26, 13], [1, 26, 9], // 2
    [1, 44, 34], [1, 44, 28], [1, 44, 22], [1, 44, 16], // 3
    [1, 70, 55], [1, 70, 44], [2, 35, 17], [2, 35, 13], // 4    
    [1, 100, 80], [2, 50, 32], [2, 50, 24], [4, 25, 9], // 5
    [1, 134, 108], [2, 67, 43], [2, 33, 15, 2, 34, 16], [2, 33, 11, 2, 34, 12], // 6
    [2, 86, 68], [4, 43, 27], [4, 43, 19], [4, 43, 15], // 7    
    [2, 98, 78], [4, 49, 31], [2, 32, 14, 4, 33, 15], [4, 39, 13, 1, 40, 14], // 8
    [2, 121, 97], [2, 60, 38, 2, 61, 39], [4, 40, 18, 2, 41, 19], [4, 40, 14, 2, 41, 15], // 9
    [2, 146, 116], [3, 58, 36, 2, 59, 37], [4, 36, 16, 4, 37, 17], [4, 36, 12, 4, 37, 13], // 10   
    [2, 86, 68, 2, 87, 69], [4, 69, 43, 1, 70, 44], [6, 43, 19, 2, 44, 20], [6, 43, 15, 2, 44, 16], // 11
    [4, 101, 81], [1, 80, 50, 4, 81, 51], [4, 50, 22, 4, 51, 23], [3, 36, 12, 8, 37, 13], // 12
    [2, 116, 92, 2, 117, 93], [6, 58, 36, 2, 59, 37], [4, 46, 20, 6, 47, 21], [7, 42, 14, 4, 43, 15], // 13
    [4, 133, 107], [8, 59, 37, 1, 60, 38], [8, 44, 20, 4, 45, 21], [12, 33, 11, 4, 34, 12], // 14
    [3, 145, 115, 1, 146, 116], [4, 64, 40, 5, 65, 41], [11, 36, 16, 5, 37, 17], [11, 36, 12, 5, 37, 13], // 15
    [5, 109, 87, 1, 110, 88], [5, 65, 41, 5, 66, 42], [5, 54, 24, 7, 55, 25], [11, 36, 12], // 16
    [5, 122, 98, 1, 123, 99], [7, 73, 45, 3, 74, 46], [15, 43, 19, 2, 44, 20], [3, 45, 15, 13, 46, 16], // 17
    [1, 135, 107, 5, 136, 108], [10, 74, 46, 1, 75, 47], [1, 50, 22, 15, 51, 23], [2, 42, 14, 17, 43, 15], // 18
    [5, 150, 120, 1, 151, 121], [9, 69, 43, 4, 70, 44], [17, 50, 22, 1, 51, 23], [2, 42, 14, 19, 43, 15], // 19
    [3, 141, 113, 4, 142, 114], [3, 70, 44, 11, 71, 45], [17, 47, 21, 4, 48, 22], [9, 39, 13, 16, 40, 14], // 20
    [3, 135, 107, 5, 136, 108], [3, 67, 41, 13, 68, 42], [15, 54, 24, 5, 55, 25], [15, 43, 15, 10, 44, 16], // 21
    [4, 144, 116, 4, 145, 117], [17, 68, 42], [17, 50, 22, 6, 51, 23], [19, 46, 16, 6, 47, 17], // 22
    [2, 139, 111, 7, 140, 112], [17, 74, 46], [7, 54, 24, 16, 55, 25], [34, 37, 13], // 23
    [4, 151, 121, 5, 152, 122], [4, 75, 47, 14, 76, 48], [11, 54, 24, 14, 55, 25], [16, 45, 15, 14, 46, 16], // 24
    [6, 147, 117, 4, 148, 118], [6, 73, 45, 14, 74, 46], [11, 54, 24, 16, 55, 25], [30, 46, 16, 2, 47, 17], // 25
    [8, 132, 106, 4, 133, 107], [8, 75, 47, 13, 76, 48], [7, 54, 24, 22, 55, 25], [22, 45, 15, 13, 46, 16], // 26
    [10, 142, 114, 2, 143, 115], [19, 74, 46, 4, 75, 47], [28, 50, 22, 6, 51, 23], [33, 46, 16, 4, 47, 17], // 27
    [8, 152, 122, 4, 153, 123], [22, 73, 45, 3, 74, 46], [8, 53, 23, 26, 54, 24], [12, 45, 15, 28, 46, 16], // 28
    [3, 147, 117, 10, 148, 118], [3, 73, 45, 23, 74, 46], [4, 54, 24, 31, 55, 25], [11, 45, 15, 31, 46, 16], // 29
    [7, 146, 116, 7, 147, 117], [21, 73, 45, 7, 74, 46], [1, 53, 23, 37, 54, 24], [19, 45, 15, 26, 46, 16], // 30
    [5, 145, 115, 10, 146, 116], [19, 75, 47, 10, 76, 48], [15, 54, 24, 25, 55, 25], [23, 45, 15, 25, 46, 16], // 31
    [13, 145, 115, 3, 146, 116], [2, 74, 46, 29, 75, 47], [42, 54, 24, 1, 55, 25], [23, 45, 15, 28, 46, 16], // 32
    [17, 145, 115], [10, 74, 46, 23, 75, 47], [10, 54, 24, 35, 55, 25], [19, 45, 15, 35, 46, 16], // 33
    [17, 145, 115, 1, 146, 116], [14, 74, 46, 21, 75, 47], [29, 54, 24, 19, 55, 25], [11, 45, 15, 46, 46, 16], // 34
    [13, 145, 115, 6, 146, 116], [14, 74, 46, 23, 75, 47], [44, 54, 24, 7, 55, 25], [59, 46, 16, 1, 47, 17], // 35
    [12, 151, 121, 7, 152, 122], [12, 75, 47, 26, 76, 48], [39, 54, 24, 14, 55, 25], [22, 45, 15, 41, 46, 16], // 36
    [6, 151, 121, 14, 152, 122], [6, 75, 47, 34, 76, 48], [46, 54, 24, 10, 55, 25], [2, 45, 15, 64, 46, 16], // 37
    [17, 152, 122, 4, 153, 123], [29, 74, 46, 14, 75, 47], [49, 54, 24, 10, 55, 25], [24, 45, 15, 46, 46, 16], // 38
    [4, 152, 122, 18, 153, 123], [13, 74, 46, 32, 75, 47], [48, 54, 24, 14, 55, 25], [42, 45, 15, 32, 46, 16], // 39
    [20, 147, 117, 4, 148, 118], [40, 75, 47, 7, 76, 48], [43, 54, 24, 22, 55, 25], [10, 45, 15, 67, 46, 16], // 40
    [19, 148, 118, 6, 149, 119], [18, 75, 47, 31, 76, 48], [34, 54, 24, 34, 55, 25], [20, 45, 15, 61, 46, 16]];
 
QRRSBlock.getRSBlocks = function (typeNumber, errorCorrectLevel) {
    var rsBlock = QRRSBlock.getRsBlockTable(typeNumber, errorCorrectLevel);
 
    if (rsBlock == undefined) {
        throw new Error("bad rs block @ typeNumber:" + typeNumber + "/errorCorrectLevel:" + errorCorrectLevel);
    }
 
    var length = rsBlock.length / 3;
    var list = new Array();
 
    for (var i = 0; i < length; i++) {
        var count = rsBlock[i * 3 + 0];
        var totalCount = rsBlock[i * 3 + 1];
        var dataCount = rsBlock[i * 3 + 2];
 
        for (var j = 0; j < count; j++) {
            list.push(new QRRSBlock(totalCount, dataCount));
        }
    }
 
    return list;
};
 
QRRSBlock.getRsBlockTable = function (typeNumber, errorCorrectLevel) {
    switch (errorCorrectLevel) {
        case QRErrorCorrectLevel.L:
            return QRRSBlock.RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 0];
 
        case QRErrorCorrectLevel.M:
            return QRRSBlock.RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 1];
 
        case QRErrorCorrectLevel.Q:
            return QRRSBlock.RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 2];
 
        case QRErrorCorrectLevel.H:
            return QRRSBlock.RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 3];
 
        default:
            return undefined;
    }
}; 
 
//---------------------------------------------------------------------
// QRBitBuffer
//---------------------------------------------------------------------
 
 
function QRBitBuffer() {
    this.buffer = new Array();
    this.length = 0;
}
 
QRBitBuffer.prototype = {
    get: function get(index) {
        var bufIndex = Math.floor(index / 8);
        return (this.buffer[bufIndex] >>> 7 - index % 8 & 1) == 1;
    },
    put: function put(num, length) {
        for (var i = 0; i < length; i++) {
            this.putBit((num >>> length - i - 1 & 1) == 1);
        }
    },
    getLengthInBits: function getLengthInBits() {
        return this.length;
    },
    putBit: function putBit(bit) {
        var bufIndex = Math.floor(this.length / 8);
 
        if (this.buffer.length <= bufIndex) {
            this.buffer.push(0);
        }
 
        if (bit) {
            this.buffer[bufIndex] |= 0x80 >>> this.length % 8;
        }
 
        this.length++;
    }
}
 
module.exports = {
    QRcode: qrcode
}